Vaccine Blocks Drug Heroin High in Tests on Monkeys

 A vaccine designed to block a heroin "high" worked in monkeys, which could open the door to human clinical trials, researchers say.

This is the first vaccine against an opioid proved to be effective at this stage of testing, according to the development team at The Scripps Research Institute in La Jolla, Calif.

The vaccine already worked in rodents.

For the new trial, four rhesus monkeys given three doses of the vaccine had an effective immune response that neutralized varying doses of heroin. The effect was strongest in the first month but lasted more than eight months after vaccination. It caused no adverse side effects, according to the researchers.

The study was published June 2 in the Journal of the American Chemical Society.

"We believe this vaccine candidate will prove safe for human trials," study leader Kim Janda said in a Scripps news release. Janda is a professor of chemistry at the institute.

Components of the vaccine already have FDA approval or have passed safety tests in previous clinical trials, Janda said.

The vaccine trains the immune system to produce antibodies that neutralize heroin molecules, preventing them from reaching the brain to cause a high.

The vaccine doesn't work against other opioid painkillers or medicines used to treat opioid addiction or overdose, the researchers said.

Blocking heroin's high could help keep many recovering addicts from relapsing into drug use, the researchers added.

The next step is finding a corporate partner for human clinical trials.